Three-blade arrangement for electrically powered knife

ABSTRACT

An electrically powered knife includes a casing enclosing an electric motor and a drive assembly for converting rotary motion of the armature shaft into reciprocal motion for a pair of blade holding members, a pair of serated blades adapted to connect with the blade holding members and positioned on both sides of and contiguous with a replaceable thin, flat blade. The serated blades are cooperating first and second support blades defining a channel adapted to receive and provide transverse support for the thin, flat blade.

United States Patent [1 1 [111 3,832,773

Langford Sept. 3, 1974 THREE-BLADE ARRANGEMENT FOR Primary ExaminerAl Lawrence Smith ELECTRICALLY POWERED KNIFE [76] Inventor: Orville L. Langford, 120 Lakeview,

New Braunfels, Tex. 78130 [22] Filed: Dec. 21, 1973 21 Appl. No.: 427,046

[52] US. Cl 30/272 A [51] Int. Cl B26b 7/00 [58] Field of Search 30/272 A, 272 R [56] References Cited UNITED STATES PATENTS 2,596,078 5/1952 Prohaska 30/272 A 3,203,095 8/1965 Nelson 30/272 A 3,316,636 5/1967 Raper et al. 30/272 A Assistant Examiner-J. T. Zatarga Attorney, Agent, or Firm-John R. Powell [57] ABSTRACT An electrically powered knife includes a casing enclosing an electric motor and a drive assembly for converting rotary motion of the armature shaft into reciprocal motion for a pair of blade holding members, a pair of serated blades adapted to connect with the blade holding members and positioned on both sides of and contiguous with a replaceable thin, flat blade. The serated blades are cooperating first and second support blades defining a channel adapted to receive and provide transverse support for the thin, flat blade.

7 Claims, 4 Drawing Figures THREE-BLADE ARRANGEMENT FOR ELECTRICALLY POWERED KNIFE BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to an electrically powered knife and more particularly is directed to an electrically powered knife featuring three contiguous cutting blades, the outer two blades being serated opposing blades adapted to hold and support between them a disposable thin, flat blade.

2. Description of the Prior Art Electric knives have become very popular in recent years and are extensively used. Most of the knives presently available comprise a pair of blades releaseably secured together and reciprocated by a suitable electric motor contained in a power unit with the blades moving in sliding contact with each other. Such knives are disclosed in US. Pat. Nos. 3,432,702; 3, 308,535 and 3, 315,356. A single bladed slicing knife is the skinning knife disclosed in US. Pat. No. 3,251,129.

I have discovered a three blade arrangement for electrically powered knives which imparts vastly improved cutting ability as compared to two blade or single blade knives. Moreover, the incorporation of a third blade is easily accomplished in an inexpensive departure from prior concepts and enables the incorporation of cheap readily available blades as the thin, flat disposable cutting blade. The three blade arrangement of this invention is suitable for adaption to a variety of the commercially available two blade electrically powered knives.

SUMMARY In summary this invention is directed to an electrically powered knife comprising a casing enclosing an electric motor and drive assembly positioned to impart reciprocal motion to a pair of serated blades, said serated blades being positioned on either side of and in contiguous relationship with a replaceable, thin, flat blade, said serated blades defining a channel adapted to receive and provide transverse support for said thin, flat blade.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE INVENTION Referring now more particularly to the drawings, FIG. 1 shows a simplified, exploded perspective view of an embodiment of this invention wherein the casing 10 serves as the handle and houses the electric motor and drive assembly. The serated blades 11 and 13 are shown attached to the handle and positioned on either side of and in contiguous relationship with the replaceable blade 12. The overlapping projection lla of blade 11 is shown although more clearly delineated in FIG.

3. FIG. 2 shows a preferred embodiment of the three blade arrangement in close up with a streamlined leading edge 13a and a keyhole slot 15, and rivet l6 arrangement holding the forward portion of the blades 11, 12 and 13 in intimate contact. As will be recognized by those skilled in the art, any readily removable connecting means can be employed in place of the keyhole slot and rivet arrangement shown in FIG. 2. A series of keyhole slots and rivets can be used for multiple replaceable blades in series as shown in FIG. I. As illustrated the blade 11 is provided with a projecting rivet 16 which passes through an aperture not shown in blade 12 and through the slot 15 provided in blade 13. With such an arrangement the support blades can be readily assembled for use or disassembled for cleaning or changing the disposable blade 12. Except for the connecting means 15 and 16 the support blades 11 and 13 differ only in that the blade 11 has a projecting top surface lla which totally or partially overlaps the top of blade 13 and seals the top of the channel formed by the support blades. This feature is shown in greater detail in FIGS. 3 and 4. Preferably the support blades are formed of stainless steel and are precision honed so as to be razor sharp. They are also provided with serated cutting edges as indicated in FIGS. 1 and 2. If desired the support blades 11 and 13 can be provided with a tungsten carbide coating to harden the surface of the blades and increase their useful life. FIG. 3 shows a cross-section of preferred support blades 11 and 13 with the space between being the channel for the disposable blade 12. FIG. 4 shows a more preferred variation on the blades of FIG. 3 in which the projecting top surface lla only partially overlaps the top of blade 13.

The replaceable blade 12 can be either a commercially available razor blade or a series of such blades, or a similar blade fabricated specifically for the eletrically powered knives of this invention. In either event, the keyhole slot and rivet, when used to connect the ends of the support blades, will be sized and positioned to hold the replaceable blade or blades in a fixed and stationary position. Preferably the replaceable blade is fixed to that support blade bearing the rivet 16 so that it reciprocates with that blade, although it can if desired be permitted to float between the reciprocating support blades.

The handle casing of the knives of this invention is conveniently molded of plastic as is well known in the art. The power unit contained in the casing can be any of those demonstrated operable in prior art devices and can be operated wither by self-contained batteries or provided with a cord for plugging into nonnal house hold alternating current outlets.

The embodiments of the invention shown in FIGS. 1 and 2 employ a three blade arrangement in which the downward projecting serations of the support blades 1 1 and 13 extend just beyond the cutting edge of the replaceable blade. As will be apparent to those skilled in the art this aspect can be modified to give a tool in which the projecting portions of the serations extend to a greater or lesser degree beyond the cutting edge of the replaceable blade, or which do not extend at all beyond the cutting edge of the replaceable blade, as may be desired.

Surprisingly the knives of this invention demonstrate exceptional effectiveness in cutting a wide variety of materials and are most exceptional in cutting baked goods and both cooked and uncooked meat, fish, fowl and vegetables. The advantages in use of the knives of this invention combined with the replaceable feature of the central blade make the knives very desirable at costs not appreciably higher than electric knives heretofore available to the public.

In view of the preceding detailed description, the use and operation of the knives of this invention will be readily apparent and understood by those skilled in the art and no further description is deemed necessary.

While particular embodiments of this invention have been illustrated and described, various changes and modifications of such embodiments will be apparent to those skilled in the art without departing from this invention in its broadest aspects. The claims annexed hereto should therefore by given a scope fully commensurate with the broadestinterpretation to which the employed language fairly admits.

I claim:

1. An electrically powered knife comprising a casing enclosing an electric motor and drive assembly positioned to impart reciprocal motion to a pair of serated blades, said serated blades being positioned on either side of and in contiguous relationship with a replaceable thin, flat blade, said serated blades defining a channel adapted to receive and provide transverse sup-. port for said thin, flat blade.

2. An electrically powered knifeof claim 1 wherein the seratet) blades are connected near their ends most remote from the handle by means of a keyhole slot and rivet.

3. An electrically powered knife of claim 1 wherein the serated blades are stainless steel and precision honed.

4. An electrically powered knife of claim 3 wherein the serated blades are coated with tungsten carbide.

5. An'electrically powered knife of claim 1 wherein one of the serated blades has a projecting top surface which overlaps thetop of the other serated blade.

6. An electrically powered knife of claim 1 wherein one of the serated blades has a projecting top surface which partially overlaps the top of the other serated blade.

7. An electrically powered knife of claim 1 wherein multiple keyhole slots and rivets connect the serated blades and hold multiple thin replaceable blades in position. 

1. An electrically powered knife comprising a casing enclosing an electric motor and drive assembly positioned to impart reciprocal motion to a pair of serated blades, said serated blades being positioned on either side of and in contiguous relationship with a replaceable thin, flat blade, said serated blades defining a channel adapted to receive and provide transverse support for said thin, flat blade.
 2. An electrically powered knife of claim 1 wherein the serate0 blades are connected near their ends most remote from the handle by means of a keyhole slot and rivet.
 3. An electrically powered knife of claim 1 wherein the serated blades are stainless steel and precision honed.
 4. An electrically powered knife of claim 3 wherein the serated blades are coated with tungsten carbide.
 5. An electrically powered knife of claim 1 wherein one of the serated blades has a projecting top surface which overlaps the top of the other serated blade.
 6. An electrically powered knife of claim 1 wherein one of the serated blades has a projecting top surface which partially overlaps the top of the other serated blade.
 7. An electrically powered knife of claim 1 wherein multiple keyhole slots and rivets connect the serated blades and hold multiple thin replaceable blades in position. 